Philip Johnson's PPG Place, located on Market Street in downtown Pittsburgh, remains a masterwork for Johnson & Burgee. The design looked to the history of American skyscrapers and revisited the notion of a series of high towers within New York's Rockefeller Center Complex. For Pittsburgh, glass has been an important industry since the 1700s. Pittsburgh Plate Glass Company or PPG's world headquarters shows the industry's prominence by its 231 glass spires. On its face, this building is impressive simply because of its sheer size. Somehow it manages to look like it has much more glass cladding than buildings of a similar size. The spires or points of glass relate to The Point, a famous gathering site in the city where the three rivers--the Ohio, Monongahela, and Allegheny--meet. Actually, Johnson designed PPG Place to be directly on axis with The Point. Like cathedral architecture of the 1200s, PPG Place emphasizes great height and boasts an interior flooded with light from above. PPG Place recalls the Gothic cathedral while reinventing the modern skyscraper. This building evokes the design of medieval spires and promotes the notion of the modern glass box. Inspired by Mies van der Rohe's modern office buildings of the 1950s, Johnson considered the skyscraper not only a symbol of modern architectural progress but of modern society. PPG is one of the city's oldest and largest companies, and this building provides a symbolic link between the old city and the city Pittsburgh has become. Physically, the building was inspired by Victoria Tower, the lesser known of the two towers that frame the Houses of Parliament in Westminster. This PPG skyscraper is 40 stories tall with five satellite buildings that extend out over a six-city block area. Source: www.drloriv.com/lectures/johnson.htm and http://glasssteelandstone.com/US/PA/PittsburghPPGPlace.html